Keeping Secrets
by cmaddict
Summary: Mac and Stella are acting suspicious, and Don Flack wants to know why. What secret could they possibly be hiding? Spoilers for Pay Up and Grounds for Deception.


**Disclaimer: **I'm not Jerry Bruckheimer or the executives at CBS, Paramount, etc. Any recognizable characters are not mine.

**A/N:** School's back in full swing, so I thought I'd go ahead and post this before life really gets crazy. This was sort of inspired from an episode of _Friends_, but I twisted it a little. I really hope you guys enjoy this. It's probably the most fun I've had writing a story because I love this character's sense of humor (it's very like my own). As always, please leave me a review and tell me how you think I did!

**Many thanks** to Lily for the read-through and comments... you're the best!

**Keeping Secrets**

Lemme tell you something about working with the CSI's.

When I first got promoted to detective, I was beyond thrilled. My old man was a cop, his old man was a cop, and there was nothing else on earth that made him prouder. I can still picture the look on his face at the promotion ceremony. It was the only time I can ever remember seeing a hint of a tear in his eyes. And that put me over the moon.

Until I found out I would be workin' with those lab rats, and I crashed down to earth real fast. Geeks with microscopes and funky chemicals, spoutin' off words I couldn't even pronounce, talkin' about Einstein and the periodic table. There was a reason high school chemistry was my nap time.

But then I got to know them after working the worst cases with them day after day after hellish day, and honestly... they weren't too bad. Sure, they reverted to nerd mode every once in a while, but they were actually sort of fun to work with. Danny and I quickly became close friends, goin' to Rangers games and such when we weren't on call. Things changed a little when he hooked up with Lindsay, but it wasn't too bad. She was a great girl, and she brought out the best in him.

Come to think of it, both of them were actually normal. When I found that out, I thought I was gonna have a heart attack.

Mac and Stella, on the other hand, were an interesting pair. Mac had been a Marine, so he ran his lab with Marine precision and that high sense of honor and integrity. He was the most honorable man I'd ever met in my life. Demanded a lot out of his people, but he was such a good leader that his people actually wanted to come through for him. Stern as hell, but I hear that things had changed after his wife died, that he was different back then.

And that was where Stella came in. From what I understand, she literally kept him alive after his wife was killed on September 11, making sure he ate and slept and showered and did everything he was supposed to. She was his best and closest friend, with this magnetic personality and vibrancy that you couldn't help but notice. In fact, most of the guys I knew at the precinct had a bit of a thing for her. They'd watch her as she flounced by, dark curls bouncing up and down, green eyes twinkling at something someone had said. Once after she left, I looked around, and I swear I saw a couple of guys with drool on the corner of their mouths. Not that I could blame them. Hell, she was gorgeous and compassionate and sexy and funny, with a smart mouth that kept everyone around her on their toes. But she was also tough as nails, and no guy would ever get that close to her if he wanted to keep his balls.

Except Mac.

Mac was one of the few guys she trusted enough to be vulnerable around. He helped her through some hellish experiences, just like she had done before. And because of that, they had this bond that was deeper than anything I'd ever seen before, like they were drawn together by some invisible magnet despite their opposite personalities. They could communicate with just a look, carrying on an entire conversation with their eyes. They were comfortable with one another to the point of finishing each other's sentences. And when they fought, oh boy. It didn't happen often, but when it did, it was like World War III. But they always made up.

Which was part of the reason I could never figure out why they didn't just give it up and date.

Everyone in the lab knew they were right for each other, even while she dated that son-of-a-bitch Frankie and he dated Peyton. They'd danced around each other for five years, and frankly, we were all sick of it. The betting pool in the lab on when or if they would finally get together grew almost daily and got to the point where the winner would almost double his or her yearly salary.

Things were getting to the point where it just had to happen.

I started suspecting something was up when Mac followed Stella to Greece to help her solve that international smuggling ring. You don't follow someone who's "just a friend" halfway around the world. When they got back, I could tell something had changed about their relationship, but I didn't know what it was.

After that... I don't talk about that.

Let's just say lots of things changed a few weeks after that, for me especially. I was in a pretty bad way after Jess and… Well, Mac and Stella helped me quite a bit, keeping me from retreating into a shell. Especially Mac. He knew how I felt, and I think Stella encouraged him to step up, which he did, admirably. As much as I didn't want pity or condolences, their friendship really did help a lot. Sometimes the three of us would get together and head out for a drink, away from the pressures of the job and the memory of her. They never tried to make me talk, but somehow I did, just because it was them.

They acted differently later, especially toward each other. At scenes, Stella gave Mac these looks that I couldn't decipher. And whenever I went looking for either one of them, I always found them together, no matter the place or the time of day. I never knew why, but something smelled… fishy. Jess had always said they would make a great couple, and while I agreed, I never thought that they actually would. They were both too damn stubborn.

However, I really started to suspect something about three months later. Danny, Hawkes, and I had caught this high-profile homicide in the East Village. I'd managed to find a witness, and I went up to the lab to hunt down one of them so we could interview her. I wandered around for a few minutes, searching for either of them, flaggin' down a few people here and there to find out where they were.

As I passed the trace lab, something down the hall caught my eye.

Actually, it was two some_ones_.

Mac and Stella stood down the hall, talking quietly with one another, which – granted – wasn't unusual. They talked to each other a lot, more so than anyone else in the lab.

It was more of the _way_ they were talking.

Stella had this little smile on her face, not a full-fledged grin, but just a little quirk at the corner of her mouth. It was almost… well, flirty, in a weird way.

The strangest thing was, on Mac's face, was an exact mirror-image of her smile. I'd never seen that kind of look from him, ever.

They were standing fairly close together, his hands in his pockets casually, hers wrapped around a file folder she clutched to her chest. I couldn't make out a word of what they were saying, but Mac was nodding slowly, that goofy smile plastered across his face.

And then he did something I would've never expected from him.

He reached out and tucked a stray curl behind her ear.

My jaw dropped. Never, _never_ had he done something like before, at least not in public. And though I would've expected her to back away uncomfortably or something, her smile just got wider.

I pulled back out of sight before they could look in my direction. There was something strange going on there. But what was it? I mean, him touching her in a manner that could be intimate wasn't exactly a confession of interest. They'd known each other for years, and she touched him like that all the time. But I remembered Jess giving me looks like Stella's sometimes when we were in public places, and Danny once told me that whenever I saw her, I got a goofy smile on my face just like the one Mac had on his.

I frowned and made a mental note to keep my eye out for something else, some sort of clue. I'm a detective; finding clues is my job, and I'm damn good at my job.

Of course, so are they…

But I didn't really notice anything else until maybe a week later. We were at a crime scene, smash-'n-grab at a jewelry store on Fifth Avenue. I'd just finished talking to the store manager when Mac and Stella pulled up in his truck. Didn't think that was too unusual; they came to scenes together quite a bit.

They walked toward me slowly, and in the dim light, I could just make out what they were wearing, and I gave a low whistle as they approached. Stella was in this killer black cocktail dress that showed off her legs, her curly hair pulled up to the back of her head. Mac was wearing a light blue tie, first time I'd seen him wear a tie in ages.

"Lookin' good tonight, Bonasera," I called as they ducked under the tape. Call me crazy, but I could've sworn I saw Mac's jaw clench a little at my remark. "Where're you goin', lookin' all pretty like that?"

Stella just grinned at me. "Dinner."

"Date? How come I haven't heard anything about this new guy?" I asked, raising my eyebrows.

"Because you're supposed to mind your own business," she retorted, her smile widening.

I returned her grin. "Where'd you go?"

"Ignacio's," Mac and Stella replied in unison. They looked at each other again, and for a moment, I thought I saw her give him that patented Bonasera glare.

Now I was really interested. "How'd you know that, Mac?"

"She, uh... I picked her up on the way over here," Mac replied, glancing at her again. "She said it was with some guy she hardly knew."

Stella nodded. I looked down at her hands. She was playing with her fingers. "Right. Met him at, uh... a musical. I probably won't see him again, though."

"Dud?" I asked.

"Yeah." She laughed, a little nervously I thought. "Not really my type."

I watched them curiously for another moment. Both of them stared back at me, just daring me to call them out or something. I didn't believe that crap for a second, but I had no proof. And all Mac would've had to do was give that look of his, and I'd be sunk for life. He might not have been my boss, but I definitely didn't want to cross a former Marine who could make me disappear with a snap of his fingers.

So I let it go, and for a time I didn't think anything else of it. We caught a big case politics-wise, and all of us were pretty busy. Finding out what they were up to slipped my mind completely.

Until about a week later.

The Mets were playin' the Cubs, and Mac offered up his apartment so we could watch the game. I kept tellin' him that he would think differently when the Cubs lost, but he said there was no way in hell that was gonna happen.

It was the seventh inning stretch. The whole gang was there, minus the girls of course – just Adam, Hawkes, Danny, Mac, Sid, and me gathered around his little TV. Mets were up three to two, and Danny had been talkin' trash to Mac, until the boss had finally gotten fed up with it and threatened to put Danny on dumpster duty for the next two months.

That shut Danny up pretty quick.

Anyway, amidst a terrible rendition of "Take Me Out to the Ballgame" sung by Sid and Adam, I excused myself to the bathroom in Mac's bedroom. As I walked through his room, a sudden flash of color caught my eye. I looked down to see a piece of lacy green cloth sticking out from under Mac's bed.

In fact, it looked a lot like underwear.

Underwear?

I bent down to look at it closer, and sure enough, it was a pair of very fancy, very lacy, very feminine panties. A smile spread over my face. Ooo, Mac was gettin' some!

Just then I heard the door open, and I looked up just in time to see Mac come into the room. He gave me a strange look. "Lose something, Don?"

"No, but I think someone else did." I motioned to the pair of panties on the floor. "You keepin' somethin' we don't know about?"

Mac's eyes went wide, and I swear I saw a blush flare up in his cheeks. "Stel," he breathed.

Whoa. Now that caught my attention. "_Stella_? These are Stella's?"

His eyes widened even more, and yep, that was definitely a blush coloring his cheeks. His eyes darted around the room, and I thought I saw a bead of sweat appear on his brow. He was nervous about something. And that was weird. "Yeah. She, uh, changed here a few nights ago."

"Why here and not her own apartment?"

"She, uh, happened to be on this side of town." His eyes lit up and a very matter-of-fact expression appeared on his face. "She'd been on a case over here and had to dig through some trash, so I told her she could clean up here. She must've dropped them when she was changing. You know her; she keeps a fresh pair of everything in her bag."

I frowned. Even though I was sure that was a load of crap, it actually sounded plausible. Damn. I'd never realized just how quick of a thinker he was before that moment. And he'd put on his poker face, so there wasn't even a hint of a smirk. Just as natural as could be.

Another shout sounded from the living room, and Mac motioned to the door. "Why don't you go get caught up on the game? I'll call her from in here and see if she wants me to bring them up to the lab tomorrow."

Before I quite knew what was happening, I'd effectively been dismissed.

I stood outside the door, my mind whirling. I was pretty sure I'd just witnessed the advent of the Apocalypse. If they were involved, I mean, it would be huge! Bigger than… well, when they said Pluto wasn't a planet! After so many years of pent-up feelings and subtle flirting, if they actually were a couple, such a revelation would be almost earth-shattering.

Plus it would really piss off Sinclair, and there's always joy in that.

That was it. I was resolved to find out what was happening with those two.

But how? Both were very private people, especially Mac. He rarely opened up about his feelings, and nobody with the exception of Stella could pry them out of him. Stella was a little more open, but even she was a hell of a secret-keeper.

I kept my eyes open for the next couple of weeks, watching both of them for signs of anything. But they kept their distance from me and from each other. I only saw them interact on a very professional level, going over case files or processing evidence. They maintained their playful banter, but there was nothing to indicate that they were involved in anything beyond a close friendship.

So if they weren't going to reveal it, I'd just have to take matters into my own hands.

In the days after Jess was murdered, we'd developed a monthly tradition. The last Thursday of every month, barring some major case, the entire team gathered at Sullivan's for some beer and pool and darts. It'd been Stella's idea, a distraction from the constant death around us, a chance to get together and just relax as friends.

Sullivan's wasn't too busy that night. A couple people sat at the bar, and an older pair of guys in suits talked quietly about something in one of the booths in the back. So we pretty much had the place to ourselves that night. Danny and Mac played pool together – Mac kickin' his ass, of course. Adam, Sid, and Hawkes were throwin' darts nearby, Sid regaling them with crazy drinking stories from his med school days.

Lindsay and Stella sat at the bar with me, watching the rest of them interact. The Messers were definitely enjoying a night without Lucy, though the girls were going ga-ga over the latest pictures of Lucy that Lindsay just had to bring along.

During a break in their conversation, I nudged Stella with my elbow. "Hey, Stel."

She turned to me, smiling. "Yeah?"

"Hey, I was just thinkin'. Y'know, about that date you were on a couple of weeks ago."

Immediately her brow knit together, and I thought I saw worry flash across her eyes. But it was soon replaced with mere curiosity. Boy, when she said she could play poker, I didn't believe her, but now I'm convinced that with that poker face, she could give Mac a run for his money.

"What about it?" she asked.

"Well, I know how you've been a little… frustrated with men lately, I guess. Lousy date after lousy date an' all that."

"Your point, Flack?"

She was getting impatient. Good. Playing right into my hand. "I was talkin' to one of the guys at the precinct, and I think he expressed a little bit of interest in you."

Stella shook her head. "Well, I'm flattered, but I'm not really –"

"You'd really like this guy, Stel. He's a good guy. Made a cocaine bust a while back that shut down an entire smuggling operation. Plays baseball and basketball. Good-lookin' too."

"I'm sure that's great, but –"

"Oh, and did I tell you he's Greek? Yeah, his grandparents are from Athens. Speaks it and everything."

She laid a hand on my arm. "Don, I really appreciate you looking out for my happiness and everything, but I'm honestly not interested in him."

"Why not? He's a lot of fun."

"I'm just not interested, that's all."

"Why?"

"Because."

"Why?"

Annoyance flashed across her face. "Because."

"I can't go back to this guy with just a 'because'. Why?"

Oh, she was really getting ticked at me. "You can just tell him I'm not interested, and that should be enough."

"But, I mean, Stel, this guy's perfect for you!"

"I can't go out with him."

"Can't? Why not?"

Her eyes flashed. "Because I'm dating Mac!" she blurted.

And then there was utter silence.

Stella's eyes went wide, and she clapped a hand over her mouth. Pool cues clattered to the ground, and every member of the team stared at her with their mouths wide open. A smirk slowly spread across my face, and I glanced at Mac. He groaned and dropped his head into his hands.

Sid was the first to recover. The M.E. cleared his throat. "How - how long?"

Mac raised his head and locked eyes with Stella. Finally he sighed and, without turning his head, replied, "About five months."

"Five months?" five voices echoed in unison.

"Since just after we got back from Greece. We wanted to be sure that this was right and that it wouldn't affect our work."

"And then the Dunbrook debacle happened, and Sinclair put the lab under a microscope," Stella added. "It just… wasn't the right time to tell you."

Silence settled over the room as they considered their words. Then Lindsay spoke up. "Are you sure? That this is right, I mean?"

Keeping his eyes locked with Stella's, Mac slowly walked around the pool table to the bar where Stella still sat with an apologetic and somewhat embarrassed look on her face. Carefully, he slid his hand around her waist, pulling her toward him. "Yes," he said softly, giving her a reassuring smile. "I'm sure."

Stella smiled and put a hand to his cheek. "Me too."

Immediately the room erupted into applause. Both their faces wore wide grins, and I couldn't help but smile when he leaned in to plant a gentle kiss on her lips. It was about freakin' time. After ten years of dancing around each other, they'd finally wised up.

Turning toward me with a hint of a grin on her face, Stella touched my arm. "You knew all along, didn't you?"

I shrugged as I cheerfully accepted fifty bucks from a grumbling Danny. "I had an inkling."

"So all that stuff about your buddy at the precinct?"

"Totally made up."

Both of them laughed, and Mac shook his head. "Always knew you were good."

"Yeah, I am, but you two are lousy at keepin' secrets."

"Oh?"

"Dude, that bit with the panties in your apartment? That wasn't exactly your smoothest moment."

They exchanged a glance, and the corners of their mouths twitched simultaneously. Finally Stella turned to me, her green eyes twinkling. "What makes you think we didn't want you to find those?"

My jaw dropped, and I stared at them. _Son of a…_

They'd played me. They'd gone and played me.

But I couldn't stop the smile from splitting my face. So I got played. I could deal with that.

_Finis_


End file.
